SproutSmart
SproutSmart Intelligent Garden Sowing

Indian Summer

Black-eyed Susan
Botanical illustration of Indian Summer
Clumping

Velvety petals unfurl in a warm, sunlit blaze—golden to amber—framing a velvety black center that seems to glow from within. Indi…

Planting Schedule

Add Indian Summer to your garden to build a schedule and get reminders.

Crop Dates

MilestoneDate
Start IndoorsFeb 6th
Last FrostMar 6th
Transplant / Sow OutdoorsMar 6th
Harvest BeginsMar 6th
Harvest EndsNov 26th

Crop Details

TraitValue
Days to MaturityN/A
Sun RequirementsFull SunFull sun
Growth HabitClumping
Support NeededNone
Planting DepthNormal
Germination Temp (°F)65
Min Soil Temp (°F)50
Min Night Temp (°F)40
Harden Off (days)7

Frequently Asked Questions


What pest or disease most often affects Rudbeckia hirta (black-eyed Susan), and how can I control it?
Rudbeckia hirta commonly gets powdery mildew in warm, humid weather with poor airflow. Water at the soil line, avoid wetting the leaves, and space plants for airflow; remove heavily infected leaves and improve sun exposure. If it keeps recurring, apply a labeled fungicide made for powdery mildew per the label and repeat as directed.
How often should I water Rudbeckia hirta during the main growing phase, and what soil moisture level should I aim for?
During active growth and bud formation, keep soil evenly moist but not soggy—about 1 inch (2.5 cm) of water per week total, adjusted for rainfall. Water when the top 1 inch of soil feels dry; Rudbeckia tolerates some drought once established, but inconsistent moisture can reduce flowering. Mulch lightly to steady moisture, and ensure drainage so roots don’t sit in water.
How do I tell when Indian Summer (Rudbeckia hirta) is ready to harvest for cut flowers or seed?
For cut flowers, harvest when the ray florets are fully extended and the central disk florets are just beginning to open—blooms should look crisp and freshly colored, not faded. For seed, leave flower heads on the plant until the central disk turns dark and dry and the seeds look firm; cut heads then dry them indoors before separating seeds.
Botanical illustration of Indian Summer

Velvety petals unfurl in a warm, sunlit blaze—golden to amber—framing a velvety black center that seems to glow from within. Indian Summer Black-eyed Susan forms sturdy, upright clumps with a graceful, airy presence, offering long-lasting blooms with a crisp, daisy-like texture that stands beautifully in the garden. Ideal for beds, borders, and naturalized drifts, it brings effortless color from early season through fall for gardeners who want dependable, showy impact.

Sowing Tips

Transplant Conditions

Wait until soil reaches 50°F and nights stay above 40°F before moving outdoors. Harden off for 7 days first.

Expert Note

For best success, sow or transplant in cool weather and keep seedlings evenly moist until established, then let Rudbeckia dry slightly between waterings.